This invention relates to bicycle frames, and more specifically to bicycle frames with an upper cross bar.
Traditionally, two basic bicycle frame designs have been manufactured and sold in this country, frames with an upper cross bar and frames without an upper cross bar. Bicycles having frames with an upper cross bar have traditionally been deemed "boys' bicycles," and bicycles having frames without an upper cross bar have traditionally been deemed "girls' bicycles." For this reason, most males feel constrained to ride only bicycles having an upper cross bar.
However, rigidly fixed upper cross bars, which are the norm in existing bicycle frame designs, pose several problems. First of all, a rigidly fixed upper cross bar makes it awkward for the rider to dismount the bicycle under normal traffic conditions. Instead of being able to merely slip forward off of the seat and step down onto the ground, the rider must swing his leg over the top of the bicycle and dismount to the side of the bicycle.
Secondly, and more importantly, a rigidly fixed upper cross bar poses a serious health risk to a rider who intentionally or unintentionally slips forwardly off of the seat under emergency conditions. In such cases, the rigid upper cross bar can do serious injury to the rider's groin, To avoid this danger, riders who wish to use a bicycle with a fixed cross bar must use a bicycle with sufficiently small wheels so that his groin does not strike the upper cross bar if he slips forward off of the seat. This is why so many all-terrain and mountain bicycles are made with small wheels. However, small wheeled bicycles are grossly less efficient on level ground than bicycles with standard size wheels.
There is, therefore, a need for a bicycle frame having an upper cross bar (so that the bicycle has an athletic and rugged appearance), but which does not cause injury to the rider when the rider straddles the upper cross bar after a stop.